1. Field of the Invention
This invention relates to a method and apparatus to convey particulate material from a location of lower elevation, such as ground level, to a relatively less accessible location of higher elevation, such as the top of a bin, vat, silo or other container, particularly on-farm storage silos.
2. Description of the Prior Art
The on-farm grain bins or silos now in common use vary in diameter from about 15 feet to 36 feet and in height from about 18 feet to 36 feet. The known feed-auger equipment for conveying grain from ground level to the loading apertures of such bins accordingly varies considerably in length, ranging from about 28 feet to about 72 feet.
In accordance with methods, practice and equipment known prior to the present invention, feed-auger equipment for the purpose indicated above has customarily been made in such a way that there are provided (a) an integral transport auger which is of one or another of some suitable number (5 to 9) of predetermined lengths, plus (b) the other equipment which is needed with an auger of that length. In other words, if there are in a manufacturer's line of transport-auger equipment eight different lengths of auger, then there are also eight different lengths of tubes, eight different auger screws, eight different drive kits, undercarriages, truss kits, etc. for each of the several different diameter augers. There is a very substantial drawback to the practice of continuing to attempt to meet the requirements of the farmers by means of having five to nine different standard lengths of transport auger, each of which has its own set of concomitant equipment. This is very costly to manufacturers and distributors of such equipment, and ultimately to the farmers and their customers. The use of a standard length auger to load grain into a particular bin or silo is based on a particular elevation of ground level which changes because of ruts, etc. This requires a re-establishment of the original ground elevation from time to time before the auger can be used.
For his part, a manufacturer requires different engineering, tooling, dies, packaging, etc., for each size of a component which performs a given function. Moreover, the manufacturer faces additional costs and expenses in connection with shipping, since each load tends to be different.
A distributor likewise faces problems. To ensure a sale, he must carry a complete line of the different sizes, and to meet his service problems, he requires a relatively large inventory of parts.
Concerning what has been known from previous patents and other references about auger equipment, it is known (e.g., from U.S. Pat. No. 3,337,068 or U.S. Pat. No. 3,719,268) that an auger encased in a tube and used for conveying particulate material can be made in two sections, with a mechanical connection such that rotary motion imparted to an auger in one of the sections is transmitted to the auger in the other.
From U.S. Pat. No. 4,142,621, there is known an auger elevator structure which comprises a mobile support, a ground-unit drivable encased-auger conveyor section so mounted upon the mobile support that its angle or attitude with respect to the ground may be adjusted, and additional conveyor sections that can be added to obtain a desired length within limits of maintaining an acceptable balance and stability. To the extent that it is possible to overcome various ones of the drawbacks mentioned above with the use of equipment which does not involve the use of anything mounted upon the silo or bin roof, the structure taught in the above-mentioned patent may suffice. As those skilled in the art will appreciate, however, the equipment of the kind described in U.S. Pat. No. 4,142,621 is necessarily somewhat limited in respect to the overall lengths and the conveying capacities which can feasibly be obtained without having a structure which becomes top-heavy. Those skilled in the art have not found in this patent any satisfactory solution to the problems of a farmer who owns a number of different bins or silos having different overall dimensions within the range indicated above and desires to load them at rates of conveying which are on the order of those that are usual with prior-art transport-auger equipment of the kind that is commercially available. Sometimes more than one feed auger is needed for utility use on the farm.
From the point of view of the farmer, the transport-auger equipment which has been commercially available prior to the present invention has also been disadvantageous in various respects other than those specifically discussed above. An auger of a given length is usually (for any silo of desirably large size) too long and awkward to be stored conveniently within existing farm buildings, and this means that any long auger is subject to wind damage, for example, by being crimped or blown over. Moreover, although it is frequently economically desirable to use a larger bin or silo, there has repeatedly been the problem that this would make the farmer's existing long auger obsolate; a relatively expensive new one would need to be purchased. Keeping several different ones, each for use with loading of trucks, wagons and loading and unloading of bins or silos of the size or sizes handled thereby, has obvious disadvantages in terms of the investment required and the space occupied by the equipment when it is not in use. There has been, from the farmer's point of view, a distinct need for equipment which is both conveniently storable and adequately versatile in respect to handling the conveying of grains to large bins or silos of different sizes and shapes.